Resisted external derotation test: How to perform and interpret

Key Takeaways

The resisted external derotation test (REDT) is a supine orthopedic assessment tool used to identify gluteal tendinopathy and greater trochanteric pain syndrome by loading the gluteal tendons under compression and tension.

A positive result reproduces the patient’s lateral hip or buttock pain during resistance; the test does not replace imaging or specialist referral, but it raises clinical suspicion with meaningful diagnostic accuracy.

Common technique errors, including insufficient external rotation and incorrect hip angle, significantly reduce the test’s validity and must be avoided for accurate results.

Pabau’s digital forms and client record tools help physical therapists and sports medicine clinicians document REDT findings, link them to treatment plans, and maintain audit-ready clinical records.

Lateral hip pain accounts for a substantial share of musculoskeletal presentations in primary care and physical therapy practices, yet it remains one of the most misdiagnosed regions in the body. The resisted external derotation test gives clinicians a fast, reliable bedside tool to determine whether the gluteal tendons are the likely pain source, narrowing the differential before imaging is ordered.

Getting the technique right matters: a poorly executed test produces false negatives, delays appropriate rehabilitation, and erodes patient confidence in the assessment process. This guide covers the full clinical picture, from anatomical rationale to step-by-step execution, interpretation, diagnostic accuracy, and what to do after a positive finding.

What is the resisted external derotation test?

The resisted external derotation test (REDT) is a clinical assessment tool designed to identify gluteal tendinopathy (GT) and greater trochanteric pain syndrome (GTPS). It was validated in a landmark study by Lequesne et al. (2008), published in Arthritis Care & Research, which established the test’s diagnostic utility for distinguishing gluteal tendon pathology from other causes of lateral hip pain.

The REDT works by simultaneously applying compressive and tensile load to the gluteus medius and gluteus minimus tendons at their insertion on the greater trochanter. When these tendons are pathological, this combined loading provokes a recognizable pain response.

Clinicians working in physical therapy, occupational therapy, and sports medicine rely on it as part of a structured hip pain assessment battery, typically alongside the FABER test and single-leg stance tests.

Anatomical basis: Why the REDT provokes pain

Understanding why the REDT provokes pain requires a brief anatomical detour. The gluteus medius and gluteus minimus originate on the outer iliac surface and insert onto the facets of the greater trochanter. In GTPS and gluteal tendinopathy, these tendons develop degenerative changes, reactive tissue, and a lower pain threshold in response to compressive load.

Two loading mechanisms act simultaneously during the REDT:

• Compressive load: when the hip is passively taken into near-maximal external rotation, the gluteal tendons wrap around and compress against the greater trochanter surface. This compression irritates pathological tendon tissue.
• Tensile load: as the patient resists the examiner’s derotation force, the gluteus medius and gluteus minimus contract eccentrically against the applied moment, placing tensile stress through the insertion.
• Combined effect: the compressive and tensile loads acting together produce a pain stimulus that, in the presence of tendon pathology, reliably reproduces the patient’s familiar lateral hip pain.

Postural factors compound this loading pattern. Sustained anterior pelvic tilt or a Trendelenburg gait increases the hip adduction moment during stance phase, adding further compressive load to gluteal tendons that are already compromised.

This dual-loading mechanism is what distinguishes the REDT from simpler hip rotation tests. Clinicians documenting biomechanical findings in detail benefit from structured client record templates that capture the specific loading context alongside the result. Consistent documentation also depends on following a clear clinical protocol versus procedure distinction, so every clinician records findings the same way.

Indications for the REDT: When to use it

Not every patient with hip pain needs the REDT. Use it when the clinical history and initial examination already point toward GTPS or gluteal tendinopathy as the primary differential.

• Lateral hip pain localized to the greater trochanter region, particularly when aggravated by lying on the affected side, crossing the legs, or climbing stairs
• Pain provoked by single-leg loading, such as walking on uneven ground or standing on one leg for prolonged periods
• Postmenopausal female patients aged 40-60, who represent the highest-prevalence demographic for GTPS
• Runners or athletes presenting with lateral hip pain after a spike in training load
• Patients where hip joint pathology (e.g. femoroacetabular impingement) has already been considered but does not fully explain the symptom distribution

The REDT is most useful when you need to confirm gluteal tendon involvement before deciding on imaging. A negative REDT in a patient with classic GTPS history does not rule out the condition entirely, but a positive result significantly raises clinical confidence.

Clinicians opening or managing a physical therapy practice can read more on structuring musculoskeletal assessment workflows in the guide to opening a therapy practice.

How to perform the REDT: Step-by-step

The resisted external derotation test requires precise patient positioning and consistent examiner technique. Small deviations in either change the loading vector and reduce the test’s validity.

Patient positioning

Position the patient supine on the exam table. Passively flex the affected hip and knee to approximately 90 degrees, then rotate the hip into near-maximal external rotation.

This starting position, hip and knee flexed to 90 degrees with the hip fully externally rotated, stretches the gluteus medius and gluteus minimus tendons over the greater trochanter and pre-loads them before any resisted force is applied.

If the test is negative in this position, repeat it with the patient prone and the hip extended, knee flexed, to load the tendons from the opposite direction.

Examiner technique and force application

Stand at the side of the table, level with the patient’s hip. With the hip and knee held in the flexed, externally rotated starting position, place one hand on the medial aspect of the knee and the other on the lateral aspect of the ankle to control the limb.

Instruct the patient to actively derotate the hip, internally rotating the thigh back toward neutral, while you resist the movement through both hands. The resistance grade should be moderate, not maximal: you are looking for pain reproduction, not strength testing. Hold the resistance for 3-5 seconds while observing the patient’s response.

A standardized approach to recording technique cues and examiner hand placement in digital assessment templates supports consistent inter-rater documentation, particularly in multi-clinician practices. Pabau’s digital forms allow practices to build custom physical assessment templates for exactly this purpose.

How to interpret the REDT

Interpretation hinges on a single criterion: does the test reproduce the patient’s familiar lateral hip or buttock pain?

• Positive REDT: the patient reports reproduction of their lateral hip pain, typically localized to the greater trochanter region or radiating into the lateral buttock. The pain must match the patient’s presenting complaint, not simply discomfort from the resistance itself.
• Negative REDT: the patient experiences no pain reproduction, or reports pain in a distribution inconsistent with gluteal tendon pathology (e.g. groin pain, posterior thigh pain).
• Equivocal result: mild discomfort that does not reproduce the familiar symptom pattern. Document this carefully and repeat the test on the contralateral limb to establish a comparison. Do not classify an equivocal result as positive.

The positive finding should be correlated with the broader clinical picture. An isolated positive REDT in a patient with atypical history warrants cautious interpretation. The REDT is a screening and assessment tool; it does not replace ultrasound or MRI when the diagnosis remains unclear after clinical assessment.

For sports medicine clinicians managing lateral hip pain in athletes, the sports medicine software available through Pabau includes outcome measure tracking alongside assessment documentation, supporting a structured clinical pathway from initial presentation to discharge.

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Pabau gives physical therapy and sports medicine practices digital forms, structured client records, and automated workflows to support consistent clinical assessment documentation, from initial REDT findings to rehabilitation outcome measures.

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Diagnostic accuracy: Sensitivity, specificity, and likelihood ratios for the REDT

The diagnostic accuracy of the resisted external derotation test has been studied in peer-reviewed literature, with the Lequesne et al. (2008) validation study providing the foundational figures. According to data cited across clinical reference sources including Physiotutors and FP Notebook, the REDT demonstrates the following diagnostic parameters for gluteal tendinopathy and GTPS:

One caveat applies: these values come from a specific study population, and positive and negative predictive values shift with disease prevalence. Interpret the numbers alongside your own pre-test probability rather than applying them uniformly across every patient.

The American Physical Therapy Association (APTA) provides clinical practice guidelines on hip pain assessment that contextualize test accuracy within broader diagnostic reasoning frameworks.

Common errors and pitfalls when performing the REDT

The resisted external derotation test is technically simple, but specific errors compromise its validity. These are the mistakes that most frequently produce misleading results in clinical practice.

• Insufficient external rotation: if the hip is not passively taken to near-maximal external rotation before resistance is applied, the tendon loading stimulus is reduced and a true positive can be missed.
• Skipping the prone follow-up: when the supine test is negative but clinical suspicion remains high, failing to repeat the test prone with the hip extended can miss a positive finding that only appears when the tendon is loaded from the opposite direction.
• Excessive force application: the REDT is not a strength test. Applying a high-grade resistance changes the nature of the stimulus from pain provocation to muscle performance testing. Use moderate, consistent force.
• Misidentifying the pain response: patients sometimes report discomfort from the pressure of the examiner’s hand or general muscle effort rather than the familiar lateral hip pain. Always ask explicitly: “Does this reproduce the pain you came in with?” and note the distribution.
• Failing to test the contralateral side: bilateral comparison is standard practice. An apparently positive result on the symptomatic side is more meaningful when the asymptomatic side produces no pain response with identical technique.

Clinicians in training or practices onboarding new physical therapy staff benefit from standardized assessment checklists. The guide to Phalen’s test demonstrates how a structured examination protocol reduces technique variability across practitioners.

Related tests used in gluteal tendinopathy assessment

The REDT is rarely used in isolation. A clinical battery gives stronger diagnostic confidence than any single test. These are the tests most commonly paired with the resisted external derotation test in GTPS assessment.

When combining tests, a positive REDT alongside a positive single-leg stance test and localized trochanteric tenderness on palpation provides strong clinical evidence for gluteal tendinopathy in the absence of imaging.

The FADIR and FABER tests are particularly useful for ruling out hip joint pathology as a competing diagnosis. For practitioners using clinical assessment tools across musculoskeletal domains, the Noble compression test illustrates how structured test batteries are applied across different joint regions.

Clinical management after a positive REDT

A positive REDT confirms the clinical hypothesis of gluteal tendinopathy or GTPS, but it is the start of the clinical decision-making process, not the end.

• Imaging referral: ultrasound is the first-line imaging modality for gluteal tendinopathy, providing real-time assessment of tendon morphology, integrity, and bursal involvement. MRI is indicated when the clinical picture is complex or when tendon tears need to be characterized before treatment decisions are made.
• Load management education: patients should be counseled to avoid positions that increase tendon compression, particularly hip adduction across midline (e.g. crossing legs, sitting with hips below knees, sleeping with the affected hip uppermost without a pillow between the knees).
• Exercise rehabilitation: progressive tendon loading is the cornerstone of GTPS management. Isometric exercises in the early irritable phase transition to isotonic and progressive functional strengthening of the gluteus medius and minimus. A graded return-to-activity plan follows strength recovery.
• Adjunct treatments: corticosteroid injection and shockwave therapy may be considered in refractory cases where conservative rehabilitation has not produced adequate improvement at 8-12 weeks. These decisions require specialist input and should be documented clearly in the patient record.

Tracking rehabilitation progress from initial assessment through to discharge requires consistent outcome measure documentation. For physical therapy practices managing GTPS caseloads, structured clinical records that link assessment findings to treatment milestones support both clinical decision-making and professional accountability.

Practices can explore how physical therapy software supports this workflow through Pabau’s practice management software overview, or review board certification and credentialing requirements in the guide to physical therapy specialties.

Pabau’s digital assessment forms and client records give physical therapy and sports medicine practices a structured way to capture REDT findings, document the clinical rationale for management decisions, and track patient progress across sessions, all within a single practice management system.

Conclusion

The resisted external derotation test is a validated, efficient, and clinically meaningful test for identifying gluteal tendinopathy and GTPS. High specificity makes a positive finding clinically significant; the key is executing the technique correctly so the result actually reflects tendon pathology rather than examiner error.

For physical therapy and sports medicine practices, the REDT works best as part of a documented assessment battery linked to a structured rehabilitation pathway. Pabau’s client record and digital forms tools make it straightforward to build exactly that kind of audit-ready clinical workflow. To see how it works in practice, book a demo with the Pabau team.

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